1. Field of the Invention
This invention relates to route markers and process of and apparatus for producing the same, and is more particularly concerned with raised highway roadmarkers of the type used to designate a prescribed lane of traffic and to a process of and apparatus for producing and installing such markers on the road surface.
2. Description of the Prior Art
In the past, raised road markers have been widely used. These markers have been in the form of "buttons", "jiggle bars" and other raised members adhered or otherwise affixed to the pavement. The markers, themselves, have been of clay, metal (aluminum and stainless steel), ceramic, and plastic (poly eurathane and polyethylene).
The following U.S. Pat. Nos. illustrate prior art markers: 2,371,462; 3,332,327 and 3,938,903. Of the above patents, U.S. Pat. No. 3,096,694 discloses the use of a two part epoxy resin for bonding the bottom surface of the marker to the roadway.
All marking devices now used, to the best of our knowledge are manufactured away from the site of the installation and subsequently installed by applying adhesive, such as an epoxy glue, to the bottom surface of the marking device. Then, the marking device is placed on the roadway surface so that the glue is sandwiched between the marking device and the surface. If properly installed, the marking device, when the adhesive drys or cures, is quite firmly held in place. Such marking devices, however, are bulky and expensive, and at time pull off, leaving the adhesive on the surface. This is perhaps due to a difference in coefficient of expansion between the "button" and the glue, which tends to loosen the button with changes in temperature. We cast the marking device or marker on the site and apply it to the surface while the resin is setting up. Thus, the material from which the marker is made, integrally bonds the marker to the surface.
The prior art markers usually cost about two and one half times as much to purchase and install as our markers cost installed.